storage/mozIStorageVacuumParticipant.idl
author Nathan Froyd <froydnj@mozilla.com>
Wed, 03 Apr 2019 00:06:04 +0000
changeset 467750 1b9e5f4b0589a636233affb84666a469a4cc4ef5
parent 244595 ad01543457e739b4eee7a245e16734a3ecfd10ad
permissions -rw-r--r--
Bug 1537643 - update cc crate; r=glandium This update from the official sources brings in the changes that we were using glandium's fork for, as well as changes enabling us to tweak more settings on Windows. Differential Revision: https://phabricator.services.mozilla.com/D25888

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface mozIStorageConnection;

/**
 * This interface contains the information that the Storage service needs to
 * vacuum a database.  This interface is created as a service through the
 * category manager with the category "vacuum-participant".
 * Please see https://developer.mozilla.org/en/mozIStorageVacuumParticipant for
 * more information.
 */
[scriptable, uuid(8f367508-1d9a-4d3f-be0c-ac11b6dd7dbf)]
interface mozIStorageVacuumParticipant : nsISupports {
  /**
   * The expected page size in bytes for the database.  The vacuum manager will
   * try to correct the page size during idle based on this value.
   *
   * @note If the database is using the WAL journal mode, the page size won't
  *        be changed to the requested value.  See bug 634374.
   * @note Valid page size values are powers of 2 between 512 and 65536.
   *       The suggested value is mozIStorageConnection::defaultPageSize.
   */
  readonly attribute long expectedDatabasePageSize;

  /**
   * Connection to the database file to be vacuumed.
   */
  readonly attribute mozIStorageConnection databaseConnection;

  /**
   * Notifies when a vacuum operation begins.  Listeners should avoid using the
   * database till onEndVacuum is received.
   *
   * @return true to proceed with the vacuum, false if the participant wants to
   *         opt-out for now, it will be retried later.  Useful when participant
   *         is running some other heavy operation that can't be interrupted.
   *
   * @note When a vacuum operation starts or ends it will also dispatch a global
   *       "heavy-io-task" notification through the observer service with the
   *       data argument being either "vacuum-begin" or "vacuum-end".
   */
  boolean onBeginVacuum();

  /**
   * Notifies when a vacuum operation ends.
   *
   * @param aSucceeded
   *        reports if the vacuum succeeded or failed.
   */
  void onEndVacuum(in boolean aSucceeded);
};